Adjustable sand blasting pretreatment device for outer wall of steel pipe

Abstract

The invention provides an adjustable sand blasting pretreatment device for the outer wall of a steel pipe. The adjustable sand blasting pretreatment device comprises a rotary driving end, a rotary clamping end, two adjustable sand blasting mechanisms, two movable driving mechanisms and two guide assemblies. The rotating driving end and the rotating clamping end are arranged at the two ends of the steel pipe correspondingly and used for making the steel pipe rotate around the axis of the steel pipe. The two adjustable sand blasting mechanisms are arranged on the two sides of the steel pipe in a bilateral symmetry mode, each movable driving mechanism is correspondingly connected with one adjustable sand blasting mechanism so as to drive the corresponding adjustable sand blasting mechanism to linearly move in the axial direction of the steel pipe, and each adjustable sand blasting mechanism is correspondingly in sliding fit with one guide assembly. According to the adjustable sand blasting pretreatment device for the outer wall of the steel pipe, the problems of unstable sand blasting energy density, local over-blasting, under-blasting or inconsistent surface roughness caused by the fact that sand blasting equipment for the outer wall of a pipeline in related technologies generally adopts a mode that a single swing arm or a fixed spray gun is matched with the pipeline to rotate are solved.

Description

Technical Field

[0001] This invention belongs to the field of steel pipe sandblasting technology, and in particular relates to an adjustable sandblasting pretreatment device for the outer wall of steel pipes. Background Technology

[0002] Existing methods for pre-treatment of pipe exteriors using sandblasting typically employ a pipe rotation and point-to-point spraying with a spray gun: a drive mechanism rotates the pipe around its own axis, while the spray gun assembly is positioned on the outside of the pipe and sprays abrasive onto the outer wall to achieve the required rust removal grade and surface roughness for coating. For complex areas such as elbows and welds, engineering applications often require adjustments to the spraying angle, distance, or trajectory to improve local treatment effectiveness; otherwise, incomplete rust removal and significant variations in anchor pattern depth may occur in these complex areas.

[0003] In pipe blasting operations, variations in pipe diameter, pipe ellipticity and rotational runout, clamping eccentricity, and pipe end bends can cause dynamic changes in the relative position between the spray gun and the pipe wall. Simultaneously, abrasive backlash and mechanical vibration during blasting further amplify the risk of spray gun attitude drift, making it difficult to maintain stable spray angles and distances. This results in fluctuations in blasting energy density and uneven local treatment, leading to poor surface roughness consistency. Since most pipe blasting equipment uses a single swing arm or fixed spray gun in conjunction with pipe rotation, the spray distance and angle between the nozzle and the pipe wall fluctuate with changes in pipe diameter, ellipticity, runout, clamping eccentricity, or pipe end bends. This leads to unstable blasting energy density, localized over-blasting, under-blasting, or inconsistent surface roughness. Furthermore, it causes nozzle or swing arm mechanisms to drift due to impact vibrations, increased wear, and repeated adjustments. Summary of the Invention

[0004] In view of this, the present invention aims to at least partially solve one of the related technical problems.

[0005] To achieve the above objectives, the technical solution of the present invention is implemented as follows:

[0006] An adjustable sandblasting pretreatment device for the outer wall of steel pipe includes a rotary drive end, a rotary clamping end, two adjustable sandblasting mechanisms, two moving drive mechanisms, and two guide components.

[0007] The rotation drive end and the rotation clamping end are respectively disposed at both ends of the steel pipe and are used to make the steel pipe rotate around its own axis.

[0008] The two adjustable sandblasting mechanisms are symmetrically arranged on both sides of the steel pipe. Each of the moving drive mechanisms is connected to one of the adjustable sandblasting mechanisms to drive the corresponding adjustable sandblasting mechanism to move linearly along the axial direction of the steel pipe. Each of the adjustable sandblasting mechanisms is slidably engaged with one of the guide components.

[0009] Each of the adjustable sandblasting mechanisms includes an arc-shaped floating frame, an arc-shaped fixed frame, a sandblasting assembly, two centering follow-up mechanisms, two floating diameter-changing mechanisms, and two telescopic swing arm mechanisms;

[0010] The two centering follow-up mechanisms are disposed inside the arc-shaped floating frame and are used to follow up with the outer wall of the steel pipe, thereby limiting the spraying distance of the sandblasting assembly relative to the outer wall of the steel pipe;

[0011] The two floating diameter changing mechanisms are connected between the arc-shaped floating frame and the arc-shaped fixed frame, which allow the arc-shaped floating frame to float radially relative to the arc-shaped fixed frame and adaptively compensate for changes in pipe diameter, ellipticity, runout, or clamping eccentricity of the steel pipe.

[0012] One end of each of the two telescopic swing arm mechanisms is hinged to the arc-shaped fixed frame, and the other end is connected to the movable support. They are used to drive the arc-shaped fixed frame to swing relative to the steel pipe and to provide support for the arc-shaped fixed frame.

[0013] Furthermore, the adjustable sandblasting mechanism also includes an adjustment mechanism, through which the sandblasting assembly is connected to the arc-shaped floating frame to adjust the spraying position and / or spraying angle of the sandblasting assembly.

[0014] Furthermore, the guide assembly includes a slide rail and a guide portion that slides with the slide rail. The slide rail is disposed in the axial direction of the steel pipe, and the guide portion is disposed on the movable support for guiding and limiting the linear movement of the movable support along the axial direction of the steel pipe.

[0015] Furthermore, the moving drive mechanism includes a stepper motor, a drive screw, and a limiting block. The output end of the stepper motor is connected to one end of the drive screw. The drive screw is threadedly engaged with the moving bracket to drive the moving bracket to move linearly along the axial direction of the steel pipe. The limiting block is disposed at the other end of the drive screw.

[0016] Furthermore, the adjustment mechanism includes a guide rail, a fixed plate, two strip holes, and two locking components. The guide rail is mounted on the arc-shaped floating frame, and the fixed plate is slidably engaged with the guide rail. The two strip holes are mounted on the arc-shaped floating frame and located on both sides of the guide rail. The fixed plate is connected to the sandblasting component through the two locking components to achieve position adjustment and locking of the sandblasting component.

[0017] Furthermore, the locking assembly includes a locking bolt, a fixing nut, and an anti-loosening washer. The locking bolt passes through the fixing nut, the anti-loosening washer, the fixing plate, and the strip hole in sequence and then engages with the sandblasting assembly through a thread to achieve locking and fixing of the sandblasting assembly.

[0018] Furthermore, the centering follow-up mechanism includes an adjusting screw, a rotating sleeve, a fixed sleeve, and a roller. One end of the adjusting screw is connected to the arc-shaped floating frame. The rotating sleeve is threadedly engaged with the adjusting screw to adjust the radial position of the fixed sleeve. The roller is located at the end of the fixed sleeve near the steel pipe and is used to roll in contact with the outer wall of the steel pipe. The rotating sleeve has a screwing part on its outer side.

[0019] Furthermore, the floating diameter reducing mechanism includes a protective sleeve, a telescopic rod structure, and a floating spring. The protective sleeve is detachably connected to the arc-shaped fixed frame via a flange plate. Both ends of the telescopic rod structure are connected to the arc-shaped floating frame and the arc-shaped fixed frame, respectively. The floating spring is sleeved outside the telescopic rod structure and located inside the protective sleeve to provide radial restoring force to the arc-shaped floating frame.

[0020] Furthermore, the telescopic swing arm mechanism includes a hinge structure, a damping rod, an electric push rod, a swing arm bracket, a servo motor, and a motor bracket. The hinge structure is mounted on the arc-shaped fixed frame and hinged to the damping rod. The electric push rod is connected between the damping rod and the swing arm bracket to adjust the telescopic state of the swing arm bracket. The servo motor is mounted on the motor bracket and its output end is driven by the swing arm bracket to realize the swing arm swing. A return spring is sleeved on the outside of the damping rod.

[0021] Furthermore, the hinge structure includes a rotating rod, a swing rod, and two fixed seats. The two fixed seats are symmetrically arranged on the outside of the arc-shaped fixed frame. The rotating rod is rotatably engaged with the two fixed seats. One end of the swing rod is connected to the rotating rod, and the other end is connected to the damping rod.

[0022] Compared with existing technologies, the adjustable sandblasting pretreatment device for the outer wall of steel pipes described in this invention has the following advantages:

[0023] 1. By setting up symmetrical centering and following mechanisms on the inner side of the arc-shaped floating frame, and arranging the sandblasting assembly between the two centering and following mechanisms, the spray distance is directly constrained by the following contact between the roller and the outer wall of the steel pipe. This means that the relative distance between the nozzle and the outer wall of the steel pipe no longer depends solely on the geometric position of the single swing arm or the fixed spray gun. As a result, a relatively stable spray distance can be maintained even when the steel pipe has ellipticity, rotational runout, or clamping eccentricity. At the same time, the stable spray distance suppresses the fluctuation of sandblasting energy density and reduces the probability of local over-spraying, under-spraying, and inconsistent roughness. The centering and following mechanism adopts a threaded adjustment method, which can realize quick initial adjustment and facilitate the switching of different pipe diameters, thereby reducing repeated machine adjustments and improving on-site adaptability.

[0024] 2. By setting up a symmetrical floating diameter-changing mechanism between the arc-shaped floating frame and the arc-shaped fixed frame, the arc-shaped floating frame has radial floating and elastic reset capabilities relative to the arc-shaped fixed frame. The floating spring provides a stable reset force for radial floating and has a certain buffering effect on external disturbances. Structurally, it achieves adaptive compensation for pipe diameter changes, ellipticity, runout, and clamping eccentricity. The protective sleeve shields the expansion and contraction area, reducing the risk of jamming caused by sandblasting dust and abrasive intrusion, making the compensation action more continuous and reliable. This radial compensation structure, in conjunction with the centering follow-up constraint, makes it easier to maintain the spray distance and spray posture under dynamic working conditions, thereby improving the consistency of sandblasting quality and reducing the wear of the mechanism caused by impact and off-center loading.

[0025] 3. A telescopic swing arm mechanism is used to provide swing support and coarse adjustment for the arc-shaped fixed frame. Damping rods and return springs are introduced into the swing arm structure to form a buffer and damping effect, making it difficult for impact vibrations caused by sandblasting backflow and unbalanced pipe rotation to be directly transmitted to the actuators and connecting hinges, thereby reducing the risk of positioning drift and accelerated wear. The servo motor drives the swing arm support through the drive disk and multiple fixed axes, which can improve the force transmission stability and reduce the posture error caused by torsional clearance. The moving support moves linearly along the axial direction under the constraint of the guide component, so that the sandblasting operation can achieve continuous coverage along the steel pipe axis and reduce manual segment repositioning. This comprehensively achieves adjustable posture, stable spray distance, and improved axial coverage efficiency.

[0026] 4. In the adjustable sandblasting mechanism on each side, two telescopic swing arms are symmetrically arranged to support and drive the arc-shaped fixed frame. Compared with the single swing arm support method commonly used in related technologies, the structure of double swing arms bearing load on the same side enables the arc-shaped fixed frame to form a more stable torque balance and torsional stiffness when subjected to sandblasting recoil force, pipeline jumping disturbance and axial movement inertial force, thereby significantly reducing the risk of deflection, sinking or swing drift that is prone to occur with single-point support. The two swing arms form vertically distributed force transmission paths with the moving bracket, which can disperse the local impact load to the two swing arms and their hinge links, avoiding the increased wear and gap of the hinge points caused by load concentration, and making it easier to maintain the same spraying posture during long-term operation. The symmetrical arrangement of the double swing arms provides the arc-shaped fixed frame with a higher degree of freedom of posture constraint, so that it can achieve a stable posture without relying on large-amplitude single-arm swing when adjusting the wrap angle or dealing with bending at the end of the steel pipe, thereby reducing the adjustment range and number of adjustments; and when combined with the damping rod and return spring, the symmetrical buffering of the two swing arms can more effectively suppress vibration coupling and resonance amplification, reduce the risk of vibration transmission and structural fatigue during the sandblasting process, and help improve the stability of sandblasting energy density and the consistency of surface roughness. Attached Figure Description

[0027] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0028] Figure 1 This is a schematic diagram of an adjustable sandblasting pretreatment device for the outer wall of a steel pipe according to an embodiment of the present invention.

[0029] Figure 2 This is a schematic diagram of the adjustable sandblasting mechanism described in an embodiment of the present invention;

[0030] Figure 3 This is a schematic diagram of the sandblasting assembly described in an embodiment of the present invention;

[0031] Figure 4 This is a schematic diagram of the locking assembly described in an embodiment of the present invention;

[0032] Figure 5 This is a schematic diagram of the centering follower mechanism described in an embodiment of the present invention;

[0033] Figure 6 This is a schematic diagram of the rotating sleeve according to an embodiment of the present invention;

[0034] Figure 7 This is a schematic diagram of the floating variable diameter mechanism described in an embodiment of the present invention;

[0035] Figure 8 This is a schematic diagram of the telescopic swing arm mechanism described in an embodiment of the present invention;

[0036] Figure 9 This is a schematic diagram of the hinge structure described in an embodiment of the present invention;

[0037] Figure 10 This is a front view of an adjustable sandblasting pretreatment device for the outer wall of a steel pipe, as described in an embodiment of the present invention.

[0038] Explanation of reference numerals in the attached figures:

[0039] 100. Steel pipe; 200. Guide assembly; 210. Moving bracket; 300. Drive screw; 400. Telescopic swing arm mechanism; 410. Hinge structure; 411. Fixed base; 412. Swing rod; 413. Rotating rod; 420. Damping rod; 430. Electric push rod; 440. Swing arm bracket; 450. Servo motor; 451. Drive disk; 460. Motor bracket; 500. Arc-shaped fixing frame; 60. 0. Arc-shaped floating frame; 700. Floating diameter changing mechanism; 710. Protective sleeve; 720. Floating spring; 800. Sandblasting assembly; 810. Mounting plate; 820. First nozzle; 830. Second nozzle; 840. Fixing plate; 850. Guide rail; 860. Locking assembly; 900. Centering follow-up mechanism; 910. Adjusting screw; 920. Rotating sleeve; 930. Fixed sleeve; 940. Roller. Detailed Implementation

[0040] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0041] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0042] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0043] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0044] This embodiment provides an adjustable sandblasting pretreatment device for the outer wall of a steel pipe, comprising a rotary drive end, a rotary clamping end, two adjustable sandblasting mechanisms, two moving drive mechanisms, and two guide components 200. The rotary drive end and the rotary clamping end are respectively disposed at both ends of the steel pipe 100 and cooperate with both ends of the steel pipe 100 to enable the steel pipe 100 to rotate around its own axis and form a stable rotational condition. The two adjustable sandblasting mechanisms are symmetrically disposed on both sides of the steel pipe 100. Each moving drive mechanism is connected to one adjustable sandblasting mechanism to drive the corresponding adjustable sandblasting mechanism to move linearly along the axial direction of the steel pipe 100. Each adjustable sandblasting mechanism is slidably engaged with one guide component 200, thereby achieving continuous axial coverage of the sandblasting area while the steel pipe 100 rotates, and reducing swaying and offset during axial movement through guide limiting.

[0045] The rotating drive end and rotating clamping end are commonly used pipe end supports and rotating drive structures in existing pipeline rotating operation equipment. They are respectively set at both ends of the steel pipe and coaxially matched with the ends of the steel pipe to provide stable and repeatable rotation conditions during sandblasting operations.

[0046] The rotating drive end applies torque to the steel pipe to drive it to rotate around its own axis. The rotating clamping end coaxially clamps and supports the end of the steel pipe and provides axial limiting to prevent the steel pipe from shifting, swaying, or becoming increasingly eccentric during rotation. To accommodate steel pipes of different diameters, the rotating drive end can be a motor output connected to a transmission component via a reduction mechanism. The transmission component is preferably a clamping turntable or chuck structure detachably connected to the end of the steel pipe. The clamping center of the turntable or chuck coincides with the axis of the steel pipe, thereby ensuring stable coaxial rotation of the steel pipe.

[0047] The rotating clamping end can employ a coaxial clamping structure such as a center support, chuck clamping, or tensioning sleeve clamping. Its clamping center coincides with the axis of the steel pipe, and axial limiting is achieved through end shoulders, limiting sleeves, or axial clamping components, ensuring the steel pipe end maintains axial stability under the influence of sandblasting recoil and its own weight. In practical implementation, the center distance between the rotating drive end and the rotating clamping end is adjustable, or its position can be adjusted via a movable mounting base to accommodate steel pipes of different lengths. The rotating clamping end can be equipped with a follower bearing or a slewing bearing to reduce rotational resistance. The rotating drive end can be coupled with frequency conversion / servo control to achieve constant speed or segmented speed regulation rotation. This ensures the coaxial rotation, anti-axial movement, and anti-sway capabilities of the steel pipe during sandblasting pretreatment without limiting the specific structural form, avoiding situations where unstable rotational conditions make it difficult to guarantee the spray distance, spray angle, and treatment uniformity.

[0048] The guide assembly 200 includes a slide rail and a guide part that slides with the slide rail. The slide rail is arranged along the axial direction of the steel pipe 100. In order to improve the guide stiffness and reduce the pitch sway of the moving support 210, in this embodiment, the slide rail of each guide assembly 200 can be two slide rails arranged symmetrically at the top and bottom. The upper and lower ends of the moving support 210 slide with the corresponding slide rails respectively, so that the moving support 210 is constrained by the upper and lower double guides when moving axially, so as to achieve guide deviation limitation and suppress the lateral shaking caused by sandblasting backflush.

[0049] The moving drive mechanism is used to drive the moving bracket 210 to move linearly along the axial direction of the steel pipe 100. Preferably, it includes a stepper motor, a drive screw 300, and a limiting block. The output end of the stepper motor is connected to one end of the drive screw 300. The drive screw 300 is threadedly engaged with the middle of the moving bracket 210 to drive the moving bracket 210 to move linearly along the axial direction of the steel pipe 100. The limiting block is set at the other end of the drive screw 300 to limit the axial movement of the drive screw 300 and to protect the end of the stroke. In actual assembly, the drive screw 300 can be supported by a bearing seat to improve the transmission smoothness. The stepper motor can be used with microstepping drive to achieve low-speed stable propulsion, so as to reduce the impact of speed fluctuations during sandblasting on the uniformity of axial coverage.

[0050] Each adjustable sandblasting mechanism includes an arc-shaped floating frame 600, an arc-shaped fixed frame 500, a sandblasting assembly 800, two centering follow-up mechanisms 900, two floating diameter changing mechanisms 700, and two telescopic swing arm mechanisms 400. The arc-shaped fixed frame 500 is located on the outside of the device and serves as the swing support and force transmission body. The arc-shaped floating frame 600 is located inside the arc-shaped fixed frame 500 and is connected to the arc-shaped fixed frame 500 through two floating diameter changing mechanisms 700. The sandblasting assembly 800 and the two centering follow-up mechanisms 900 are both located inside the arc-shaped floating frame 600. The two centering follow-up mechanisms 900 are arranged symmetrically above and below and are used to follow up and contact the outer wall of the steel pipe 100. This allows the spray distance of the sandblasting assembly 800 relative to the outer wall of the steel pipe 100 to be limited even when the steel pipe 100 has ellipticity, runout, or clamping eccentricity. The sandblasting assembly 800 is located between the two centering follow-up mechanisms 900 to form a relatively stable spraying action zone under the constraint of follow-up centering, thereby reducing the sensitivity of the spray distance and spray angle to fluctuations with working conditions.

[0051] The centering follow-up mechanism 900 includes an adjusting screw 910, a rotating sleeve 920, a fixed sleeve 930, and a roller 940. One end of the adjusting screw 910 is connected to the inner wall of the arc-shaped floating frame 600. The rotating sleeve 920 is threadedly engaged with the adjusting screw 910 to achieve axial forward and backward adjustment and drive the fixed sleeve 930 to move closer to or further away from the outer wall of the steel pipe 100 in the radial direction, thereby completing the initial manual adjustment of the spray distance. The inner end of the fixed sleeve 930 is rotatably engaged with the rotating sleeve 920 to prevent the fixed sleeve 940 from being driven during screwing adjustment. The rotation of the 30 affects the follow-up contact stability of the roller 940. The preferred rotational engagement method is as follows: the inner end of the rotating sleeve 920 is provided with an annular protrusion, which rotates and engages with the annular groove on the inner wall of the outer end of the fixed sleeve 930, thereby forming an axially limited and relatively rotatable connection; the roller 940 is located at the end of the fixed sleeve 930 near the steel pipe 100 and is used to roll and contact the outer wall of the steel pipe 100 to reduce friction and wear; the outer side of the rotating sleeve 920 is provided with a screwing part for quick on-site adjustment.

[0052] A floating diameter reducing mechanism 700 is connected between the arc-shaped floating frame 600 and the arc-shaped fixed frame 500 and is symmetrically arranged vertically. It allows the arc-shaped floating frame 600 to float radially relative to the arc-shaped fixed frame 500 and adaptively compensates for changes in the pipe diameter, ellipticity, runout, or clamping eccentricity of the steel pipe 100. The floating diameter reducing mechanism 700 includes a protective sleeve 710, a telescopic rod structure, and a floating spring 720. The end of the protective sleeve 710 is detachably connected to the arc-shaped fixed frame 500 via a flange plate for easy maintenance and replacement. Both ends of the telescopic rod structure are connected to the arc-shaped floating frame 600 and the arc-shaped fixed frame 500 respectively to provide radial telescopic guidance. The floating spring 720 is sleeved outside the telescopic rod structure and located inside the protective sleeve 710 to provide radial restoring force to the arc-shaped floating frame 600. By shielding the floating spring 720 and the telescopic rod structure with the protective sleeve 710, the risk of sandblasting dust and abrasive entering the telescopic mating area and causing jamming can be reduced, and the radial floating compensation can be made more stable and reliable.

[0053] The sandblasting assembly 800 is connected to the arc-shaped floating frame 600 via an adjustment mechanism to adjust the spray position and / or spray angle of the sandblasting assembly 800 and reliably lock it after adjustment. The sandblasting assembly 800 includes a mounting plate 810 and two nozzle assemblies. The mounting plate 810 is located inside the arc-shaped floating frame 600. The two nozzle assemblies are symmetrically spaced back and forth along the axial direction of the steel pipe 100 inside the mounting plate 810 to expand the coverage width and reduce the number of axial reciprocating strokes. Each nozzle assembly includes a mounting frame, a first nozzle 820, and a second nozzle 830. The first nozzle 820 and the second nozzle 830 are symmetrically arranged on the mounting frame to cooperate with the upper and lower double-centering follow-up constraint to form a more uniform spray distribution. The mounting frame is fixedly connected to the mounting plate 810. The first nozzle 820 and the second nozzle 830 are detachably connected to the mounting frame to meet the requirements of easy replacement of nozzles. Screw connection is preferred to achieve foolproof and quick disassembly and assembly.

[0054] The adjustment mechanism includes a guide rail 850, a fixing plate 840, two slotted holes, and two locking components 860. The guide rail 850 is mounted on the arc-shaped floating frame 600 and extends along a predetermined adjustment direction. The fixing plate 840 is located on the outside of the arc-shaped floating frame 600 and slides with the guide rail 850 to achieve relative displacement adjustment of the sandblasting component 800 on the arc-shaped floating frame 600. The two slotted holes are opened on the arc-shaped floating frame 600 and located on both sides of the guide rail 850 to provide locking stroke and adjustment margin. The fixing plate 840 is connected to the sandblasting component 800 through the two locking components 860 to achieve position adjustment and locking. To improve locking reliability and reduce the risk of loosening, anti-slip pads can be provided on the front and rear sides of the inner wall of the fixing plate 840 to increase friction and disperse clamping stress. At the same time, stops can be provided at the beginning and end of the guide rail 850 to limit the sliding stroke of the fixing plate 840 and avoid interference caused by over-adjustment. The locking assembly 860 includes a locking bolt, a fixing nut, and an anti-loosening washer. The locking bolt passes through the fixing nut, the anti-loosening washer, the fixing plate 840, and the strip hole in sequence and then engages with the sandblasting assembly 800 through a thread. By tightening the locking bolt, the fixing plate 840 and the arc-shaped floating frame 600 are clamped and locked, so that the spraying position can still be kept stable under sandblasting back jet and vibration conditions.

[0055] The telescopic swing arm mechanism 400 is used to drive the arc-shaped fixed frame 500 to swing relative to the steel pipe 100 and to provide support for the arc-shaped fixed frame 500. It is symmetrically arranged vertically and hinged to the outer side of the arc-shaped fixed frame 500, and its other end is connected to the movable bracket 210. To improve installation rigidity and facilitate the arrangement of driving components, the inner side of the movable bracket 210 can be symmetrically arranged with fixed inclined surfaces vertically. Each fixed inclined surface is used to connect and fix to the motor bracket 460 of the corresponding telescopic swing arm mechanism 400, so that the force direction of the swing arm is more stable and consistent with the swing plane. The telescopic swing arm mechanism 400 includes a hinge structure 410, a damping rod 420, an electric push rod 430, a swing arm bracket 440, a servo motor 450, and a motor bracket 460. The hinge structure 410 is mounted on the arc-shaped fixed frame 500 and hinged to the damping rod 420. The electric push rod 430 is connected between the damping rod 420 and the swing arm bracket 440 to adjust the telescopic state of the swing arm bracket 440 and to achieve coarse adjustment of the arc-shaped fixed frame 500. The servo motor 450 is mounted on the motor bracket 460 and its output end is driven by the swing arm bracket 440 to achieve swing arm swing adjustment. To improve the force transmission stability of the drive connection, a drive disk 451 can be set at the output end of the servo motor 450. The drive disk 451 is connected to the end of the swing arm bracket 440 through multiple fixed shafts to form a multi-point connection and reduce the gap and torsional error of the single-point connection. A return spring is sleeved on the outside of the damping rod 420. One end of the return spring abuts against the hinge structure 410, and the other end abuts against the mounting seat set on the damping rod 420. This buffers the impact vibration and provides a return force during the swing and extension adjustment process, so that the swing arm system can still have better posture maintenance ability under force disturbance during sandblasting operation.

[0056] The hinge structure 410 includes a rotating rod 413, a swing rod 412, and two fixed seats 411. The two fixed seats 411 are symmetrically arranged on the outside of the arc-shaped fixed frame 500. The rotating rod 413 and the two fixed seats 411 are rotatably engaged to form a stable rotating pair. One end of the swing rod 412 is connected to the rotating rod 413, and the other end is connected to the damping rod 420, thereby coupling the swing freedom of the arc-shaped fixed frame 500 with the extension and retraction adjustment of the damping rod 420 and the electric push rod 430, and forming an adjustable and buffered swing arm support structure in terms of structure.

[0057] like Figure 10As shown, in this embodiment, to ensure that the spray direction and spray distance control of the sandblasting assembly have a consistent geometric reference, and to make the centering follow-up, radial floating compensation, and swing arm swing adjustment all realize around the same reference axis, the arrangement reference of each related mechanism is symmetrically positioned with the pipe axis of the steel pipe 100 as the center; the two centering follow-up mechanisms 900 are arranged radially opposite to each other along the steel pipe 100 and symmetrically arranged vertically, so that the force line of the roller 940 of the follow-up part that contacts the outer wall of the steel pipe 100 passes through the pipe axis of the steel pipe 100, thereby forming a centering follow-up constraint with the pipe axis as the reference during the rotation of the steel pipe 100, which is used to stably limit the spray distance of the sandblasting assembly 800 relative to the outer wall of the steel pipe 100.

[0058] Two floating diameter reducing mechanisms 700 are symmetrically arranged vertically and connected between the arc-shaped floating frame 600 and the arc-shaped fixed frame 500. This makes the extension and retraction guide direction of the floating diameter reducing mechanism 700 consistent with the radial direction of the steel pipe 100, and the equivalent action lines of the upper and lower floating diameter reducing mechanisms 700 are symmetrical about the pipe axis of the steel pipe 100. This allows the radial floating compensation of the arc-shaped floating frame 600 relative to the arc-shaped fixed frame 500 to be achieved with the pipe axis of the steel pipe 100 as the center, avoiding additional sway or torsion.

[0059] Two telescopic swing arm mechanisms 400 are symmetrically arranged vertically, and their hinge points with the arc-shaped fixed frame 500 and their connection points with the movable support 210 are symmetrically arranged about the axis of the steel pipe 100. This allows the two telescopic swing arm mechanisms 400 to form a symmetrical support and swing adjustment force system around the axis of the steel pipe 100. Therefore, even when the wrap angle or posture of the arc-shaped fixed frame 500 is changed, the spraying center area of ​​the sandblasting assembly 800 can still maintain a stable relative relationship with the axis of the steel pipe 100, reducing the risk of attitude drift caused by unilateral force. The above-mentioned "coincidence / symmetry" refers to the alignment relationship in the geometric reference sense. Reasonable deviations are allowed within the manufacturing and assembly tolerance range, but the purpose is to ensure that the equivalent lines of action of the relevant mechanisms establish a unified centering and compensation reference centered on the axis of the steel pipe 100.

[0060] The abrasive supply section adopts an existing sandblasting material supply structure, which continuously supplies abrasive and carrier gas to the sandblasting assembly 800 to meet the blasting requirements and is connected and coordinated with the sandblasting assembly 800. The abrasive supply section may include an abrasive storage container, a sand supply pipeline, and a sandblasting hose connected to the sand supply pipeline. The abrasive storage container is used to store sandblasting abrasive, the sand supply pipeline is used to transport the abrasive from the abrasive storage container to the sandblasting assembly 800, and the sandblasting hose is used to connect to the nozzle end or sandblasting gun end of the sandblasting assembly 800 to realize abrasive delivery. To ensure stable abrasive delivery, the abrasive supply section may be equipped with conventional screens / filters to remove agglomerated particles, and conventional regulating valves may be installed to adjust the abrasive supply, so that the sandblasting assembly 800 obtains a continuous and stable abrasive supply during the rotation of the steel pipe 100 and the axial movement of the adjustable sandblasting mechanism. The sand supply section can be connected to the sandblasting assembly 800 using existing connection methods such as threaded joints, quick-connect joints, or flange joints. The sand supply pipeline can be flexibly arranged to follow the swing and axial movement of the adjustable sandblasting mechanism to avoid pulling interference during movement. The sand supply section is a mature existing structure in the field and is not shown in the attached drawings. This embodiment does not limit its specific form, as long as it can be connected to the sandblasting assembly 800 and achieve stable sand supply.

[0061] Based on the aforementioned sand supply section, this device can be equipped with a control mechanism as an electrical control unit to achieve coordinated operation with various electrical components. The control mechanism can be a general-purpose control unit such as a PLC, microcontroller, or industrial computer. It is electrically connected to the drive motor of the rotary drive end, the stepper motors of the two moving drive mechanisms, the servo motors 450 of the two telescopic swing arm mechanisms, and the electric push rods 420 of the two telescopic swing arm mechanisms, respectively, to achieve coordinated control of the rotation of the steel pipe 100, the axial movement of the adjustable sandblasting mechanism, and the swing adjustment of the swing arm. The control mechanism can also be electrically connected to the conventional start / stop / adjustment elements of the sand supply section to achieve coordination between the start / stop of the sand supply and the operating rhythm. For example, the sand supply can be turned on before sandblasting begins and turned off when sandblasting ends or returns, or the sand supply can be adjusted according to preset parameters in different sections. The control mechanism can be equipped with a human-machine interface for inputting process parameters such as steel pipe specifications, sandblasting stroke and running speed, and output corresponding control commands according to a preset program, so that the adjustable sandblasting mechanisms on both sides of the steel pipe move at a set axial speed and match the sand supply state during the rotation of the steel pipe. The above-mentioned control mechanism and its connection with the sand supply part and various electrical components can all be implemented using conventional technologies in the field. This embodiment does not require control algorithms or control structures as necessary limitations, and allows the use of relay control, driver control or other equivalent control methods to complete the same function.

[0062] How this example works

[0063] Step 1: Clamp the steel pipe 100 between the rotating drive end and the rotating clamping end, so that both ends of the steel pipe 100 are coaxially engaged with the rotating drive end and the rotating clamping end and obtain axial limiting and support conditions. Then start the rotating drive end to test rotate at low speed to confirm that the steel pipe 100 rotates smoothly and without obvious swaying or swinging.

[0064] Step 2: Move the two adjustable sandblasting mechanisms to the initial positions on the left and right sides of the steel pipe 100, so that the arc-shaped fixed frame 500 and the arc-shaped floating frame 600 form corresponding envelope positions around the steel pipe 100; through the guiding component 200 to guide and constrain the moving support 210, adjust the posture of the moving support 210 so that it can smoothly slide with the slide rail and has the conditions to move linearly along the axial direction of the steel pipe 100.

[0065] Step 3: Perform initial spray distance adjustment. Tighten the rotating sleeve 920 of the centering follower mechanism 900 to drive the fixed sleeve 930 radially forward and backward until the roller 940 forms a stable rolling contact with the outer wall of the steel pipe 100. Under the combined action of the upper and lower centering follower mechanisms 900, the equivalent action lines of the two rollers 940 pass through the axis of the steel pipe 100, thereby establishing a centering follower constraint based on the axis of the steel pipe 100 and completing the initial setting of the spray distance of the sandblasting assembly 800 relative to the outer wall of the steel pipe 100.

[0066] Step four: Perform coarse adjustment of the position of the sandblasting component. After loosening the locking component 860 of the adjustment mechanism, slide the fixing plate 840 along the direction of the guide rail 850 to drive the sandblasting component 800 to move relative to the arc-shaped floating frame 600, thereby determining the spraying position or spraying angle of the sandblasting component 800. Then tighten the locking component 860 to complete the locking, and check that the fixing plate 840 is in a stable state within the stop range of the beginning and end of the guide rail 850 to avoid displacement drift caused by sandblasting backlash.

[0067] Step 5: Perform rough adjustment of the swing angle and telescopic extension. Based on the pipe diameter, end bend, or local shape of the steel pipe 100, adjust the telescopic state of the swing arm bracket 440 through the electric push rod 430 of the telescopic swing arm mechanism 400, and drive the swing arm bracket 440 to swing through the servo motor 450, so that the arc-shaped fixed frame 500 forms the desired envelope angle and spray coverage range relative to the steel pipe 100. During the adjustment process, the damping rod 420 and the return spring buffer and suppress the impact and rebound, making it easier to maintain the stable posture of the swing arm.

[0068] Step 6: Complete the sand supply preparation and connect it to the sandblasting assembly. Connect the sandblasting hose of the sand supply section to the nozzle end or sandblasting gun end of the sandblasting assembly 800 using the existing connector connection method. Confirm that the abrasive in the abrasive storage container is in normal condition, the pipeline is not blocked, and the valves are in an adjustable state. Set the sand supply volume and sandblasting start and stop conditions according to the pretreatment requirements of the outer wall of the steel pipe 100, so that the sand supply section has the ability to stably supply sand during the sandblasting process.

[0069] Step 7, Start the linkage sandblasting operation: The control mechanism sequentially starts the rotation of the steel pipe 100, the sand supply, and the sandblasting component 800 according to the preset program; at the same time, the two moving drive mechanisms are started, so that the drive screw 300 drives the moving bracket 210 to move linearly along the axial direction of the steel pipe 100, so that the sandblasting area is continuously covered along the axial direction of the steel pipe 100; during the sandblasting process, the floating diameter changing mechanism 700 allows the arc-shaped floating frame 600 to float radially relative to the arc-shaped fixed frame 500 under the action of the floating spring 720, so as to adaptively compensate for the ellipticity, rotational runout, or clamping eccentricity of the steel pipe 100, and maintain the spray distance stability under the follow-up constraint of the centering follow-up mechanism 900, so that the sandblasting energy density and the treatment effect are consistent.

[0070] Step 8: When insufficient local spray coverage is detected, the spray posture is deviated due to the bending edge of the steel pipe 100 end, or the posture of the mechanism is disturbed due to sandblasting backlash, the axial advance is paused or the speed is reduced by controlling the mechanism, and the telescopic swing arm mechanism 400 is driven to swing and extend the arc-shaped fixed frame 500 for fine adjustment. If necessary, the position of the sandblasting component 800 is finely adjusted again with the adjustment mechanism and locked again. After the adjustment is completed, the rotation and axial advance are resumed and the sandblasting process continues.

[0071] Step 9, End of Operation and Reset Maintenance: After sandblasting is completed, the control mechanism sequentially shuts off sandblasting and sand supply and stops the rotation of steel pipe 100, so that the two adjustable sandblasting mechanisms return to the maintenance position under the action of the moving drive mechanism; depending on the wear condition, disassemble and replace the first nozzle 820 and the second nozzle 830 or clean the sand supply pipeline, and perform routine inspection and cleaning on the centering follow-up mechanism 900, the floating diameter changing mechanism 700 and the guide assembly 200 to complete the preparation for the next operation.

[0072] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adjustable sandblasting pretreatment device for the outer wall of steel pipes, characterized in that: It includes a rotary drive end, a rotary clamping end, two adjustable sandblasting mechanisms, two moving drive mechanisms, and two guide components (200); The rotation drive end and the rotation clamping end are respectively disposed at both ends of the steel pipe (100) and are used to make the steel pipe (100) rotate around its own axis; Two adjustable sandblasting mechanisms are symmetrically arranged on both sides of the steel pipe (100). Each of the moving drive mechanisms is connected to one of the adjustable sandblasting mechanisms to drive the corresponding adjustable sandblasting mechanism to move linearly along the axial direction of the steel pipe (100). Each of the adjustable sandblasting mechanisms is slidably engaged with one of the guide components (200). Each of the adjustable sandblasting mechanisms includes an arc-shaped floating frame (600), an arc-shaped fixed frame (500), a sandblasting assembly (800), two centering follow-up mechanisms (900), two floating diameter changing mechanisms (700), and two telescopic swing arm mechanisms (400). The two centering follow-up mechanisms (900) are disposed inside the arc-shaped floating frame (600) and are used to follow up with the outer wall of the steel pipe (100) to limit the spraying distance of the sandblasting assembly (800) relative to the outer wall of the steel pipe (100); The two floating diameter changing mechanisms (700) are connected between the arc-shaped floating frame (600) and the arc-shaped fixed frame (500) to allow the arc-shaped floating frame (600) to float radially relative to the arc-shaped fixed frame (500) and to adaptively compensate for changes in pipe diameter, ellipticity, runout or clamping eccentricity of the steel pipe (100). One end of each of the two telescopic swing arm mechanisms (400) is hinged to the arc-shaped fixed frame (500), and the other end is connected to the movable bracket (210), which is used to drive the arc-shaped fixed frame (500) to swing relative to the steel pipe (100) and to provide support for the arc-shaped fixed frame (500).

2. The adjustable sandblasting pretreatment device for the outer wall of steel pipe according to claim 1, characterized in that: The adjustable sandblasting mechanism further includes an adjustment mechanism, through which the sandblasting assembly (800) is connected to the arc-shaped floating frame (600) to adjust the spraying position and / or spraying angle of the sandblasting assembly (800).

3. The adjustable sandblasting pretreatment device for the outer wall of steel pipe according to claim 1, characterized in that: The guide assembly (200) includes a slide rail and a guide part that slides with the slide rail. The slide rail is disposed in the axial direction of the steel pipe (100), and the guide part is disposed on the movable support (210) for guiding and limiting the linear movement of the movable support (210) along the axial direction of the steel pipe (100).

4. The adjustable sandblasting pretreatment device for the outer wall of steel pipe according to claim 1, characterized in that: The moving drive mechanism includes a stepper motor, a drive screw (300), and a limiting block. The output end of the stepper motor is connected to one end of the drive screw (300). The drive screw (300) is threadedly engaged with the moving bracket (210) to drive the moving bracket (210) to move linearly along the axial direction of the steel pipe (100). The limiting block is located at the other end of the drive screw (300).

5. An adjustable sandblasting pretreatment device for the outer wall of a steel pipe according to claim 2, characterized in that: The adjustment mechanism includes a guide rail (850), a fixing plate (840), two strip holes, and two locking components (860). The guide rail (850) is disposed on the arc-shaped floating frame (600), and the fixing plate (840) is slidably engaged with the guide rail (850). The two strip holes are disposed on the arc-shaped floating frame (600) and located on both sides of the guide rail (850). The fixing plate (840) is connected to the sandblasting assembly (800) through the two locking components (860) to realize the position adjustment and locking of the sandblasting assembly (800).

6. An adjustable sandblasting pretreatment device for the outer wall of a steel pipe according to claim 5, characterized in that: The locking assembly (860) includes a locking bolt, a fixing nut, and an anti-loosening washer. The locking bolt passes through the fixing nut, the anti-loosening washer, the fixing plate (840), and the strip hole in sequence and then engages with the sandblasting assembly (800) by thread to achieve locking and fixing of the sandblasting assembly (800).

7. An adjustable sandblasting pretreatment device for the outer wall of a steel pipe according to claim 1, characterized in that: The centering follower mechanism (900) includes an adjusting screw (910), a rotating sleeve (920), a fixed sleeve (930), and a roller (940). One end of the adjusting screw (910) is connected to the arc-shaped floating frame (600). The rotating sleeve (920) is threadedly engaged with the adjusting screw (910) to adjust the radial position of the fixed sleeve (930). The roller (940) is located at the end of the fixed sleeve (930) near the steel pipe (100) and is used to roll in contact with the outer wall of the steel pipe (100). The rotating sleeve (920) has a screwing part on its outer side.

8. An adjustable sandblasting pretreatment device for the outer wall of a steel pipe according to claim 1, characterized in that: The floating diameter reducing mechanism (700) includes a protective sleeve (710), a telescopic rod structure, and a floating spring (720). The protective sleeve (710) is detachably connected to the arc-shaped fixed frame (500) via a flange plate. The two ends of the telescopic rod structure are respectively connected to the arc-shaped floating frame (600) and the arc-shaped fixed frame (500). The floating spring (720) is sleeved on the outside of the telescopic rod structure and located inside the protective sleeve (710) to provide radial restoring force to the arc-shaped floating frame (600).

9. An adjustable sandblasting pretreatment device for the outer wall of a steel pipe according to claim 1, characterized in that: The telescopic swing arm mechanism (400) includes a hinge structure (410), a damping rod (420), an electric push rod (430), a swing arm bracket (440), a servo motor (450), and a motor bracket (460). The hinge structure (410) is mounted on the arc-shaped fixed frame (500) and hinged to the damping rod (420). The electric push rod (430) is connected between the damping rod (420) and the swing arm bracket (440) to adjust the telescopic state of the swing arm bracket (440). The servo motor (450) is mounted on the motor bracket (460), and its output end is driven by the swing arm bracket (440) to realize the swing arm swing. A return spring is sleeved on the outside of the damping rod (420).

10. An adjustable sandblasting pretreatment device for the outer wall of a steel pipe according to claim 9, characterized in that: The hinge structure (410) includes a rotating rod (413), a swing rod (412), and two fixed seats (411). The two fixed seats (411) are symmetrically arranged on the outside of the arc-shaped fixed frame (500). The rotating rod (413) is rotatably engaged with the two fixed seats (411). One end of the swing rod (412) is connected to the rotating rod (413), and the other end is connected to the damping rod (420).

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